Conventional synthetic aperture radar (SAR) systems generate an effectively long antenna by signal processing rather than actually using a long physical antenna. In a conventional SAR system, radar signals are transmitted and return signals are received with a relatively small physical antenna as the antenna travels in a straight line and at a near constant velocity. SAR systems generate higher-resolution images because they are not limited by their antenna beamwidth.
Conventional SAR systems are generally not suitable for human-held or vehicular mounted uses because the motion of the radar/imaging unit is unpredictable and difficult to measure. Because SAR is difficult to use for these ground based radar systems, the resolution of such systems is generally limited by a small antenna's physical beamwidth. Another problem with some ground-based SAR systems is that they work only at close range. This may present safety problems among other difficulties.
Thus, there are general needs for synthetic aperture imaging systems and methods that compensate for complex motion of persons or vehicles. There are also general needs for synthetic aperture imaging systems and methods that can generate images of targets through obstacles. There are also general needs for synthetic aperture imaging systems and methods that compensate for complex motion and can detect, locate and classify an image behind an obstacle. There are also general needs for synthetic aperture imaging systems and methods that generate synthetic aperture images at greater ranges.